Panel 1: Okay Killer, What do you want for your last meal?
Panel 2: The Executioner.

But wait doesn't this create a paradox?

If he eats the executioner, then that person is dead and can't be the executioner -- some other person will have to step in to be the executioner.
Which means that the person he did get is not the executioner and therefore,
should not be the person that he gets. Which means that he lives, and can be the executioner,
which means ...

Eating the executioner, [insert oral sex joke here]. But, on a more serious note, it also doesn't have to be lethal- you can cut off a piece of the executioner (probably a forearm or something, although a clever executioner can stuff a minced cancer tumor into a hollowed out appendix and a call it sausage) without killing them, if you suture the wound back up.